flake8-noqa

flake8 plugin to validate # noqa comments.

flake8 is very particular about formatting of # noqa comments. If your # noqa isn't exactly what flake8 expects, it can easily cause your # noqa comment to be ignored.

However, forgetting a colon or adding an extra space in the wrong place will turn a strict # noqa: <code> comment into a blanket # noqa comment, which is likely not what you intended. For example: # noqa F841, # noqa : F841, and # noqa: F841 will be interpreted as # noqa and may, as a result, hide other errors you care about.

This plugin looks for noqa comments that do not match the proper formatting so your # noqa comments work and do only what you expect them to.

Optionally, it can also enforce usage of codes with all # noqa comments.

In addition, this plugin looks for # noqa comments that are unnecessary because either there are no matching violations on the line or they contain codes that do not match existing violations.

Errors reported by this module cannot be prevented via # noqa comments, otherwise you'd never see many of the errors it produces. Use ignore, extend-ignore, or per-file-ignores to ignore them as needed. Alternatively, if you have a comment that this plugin thinks is a # noqa with codes, but isn't, e.g. # noqa : X100 is not a code, you can make the comment look less like a proper # noqa comment. e.g. # noqa - X100 is not a code (flake8 will interpret both of those as # noqa).

Usage Note: When determining if violations have matched a # noqa comment, this plugin requires flake8 to have been made aware of the violations that would otherwise apply. Some plugins do their own processing of # noqa comments and stop sending violation reports to flake8 when they see a # noqa comment. A plugin doing so will cause this plugin to stop seeing the violation, and it may report the lack of a violation or matching code. When you then remove the # noqa comment or violation code, the other plugin will resume sending the violation, prompting you to restore the # noqa comment or code.

The best fix for this situation is to try to get the offending plugin to stop respecting # noqa comments. A plugin doing so is considered an anti-pattern, and it's best to allow flake8 to determine if violations should be surfaced to the user or not. The offending plugin may have an option to control this behavior (note the flake8 --disable-noqa option will disable all noqa comments, so is not a suitable fix for this situation). If the plugin does not have an option to control its # noqa behavior, the best course of action may be to contact the maintainers of the plugin via the appropriate issue reporting system.

If the plugin is unmaintained, or the maintainers decline to address the issue for whatever reason, feel free to file an issue on this plugin to see if a work-around can be established.

Installation

Standard python package installation:

pip install flake8-noqa

Options

noqa-require-code : Require code(s) to be included in # noqa comments

noqa-no-require-code : Do not require code(s) in # noqa comments (default setting)

noqa-include-name : Include plugin name in messages

noqa-no-include-name : Do not include plugin name in messages (default setting)

All options may be specified on the command line with a -- prefix, or can be placed in your flake8 config file.

Error Codes

Code	Message
NQA001	"#noqa" must have a single space after the hash, e.g. "# noqa"
NQA002	"# noqa X000" must have a colon, e.g. "# noqa: X000"
NQA003	"# noqa : X000" must not have a space before the colon, e.g. "# noqa: X000"'
NQA004	"# noqa:  X000" must have at most one space before the codes, e.g. "# noqa: X000"
NQA005	"# noqa: X000, X000" has duplicate codes, remove X000
NQA011	"#flake8: noqa" must have a single space after the hash, e.g. "# flake8: noqa"
NQA012	"# flake8 noqa" must have a colon or equals, e.g. "# flake8: noqa"
NQA013	"# flake8 : noqa" must not have a space before the colon, e.g. "# flake8: noqa"
NQA101	"# noqa" has no violations
NQA102	"# noqa: X000" has no matching violations
NQA103	"# noqa: X000, X001" has unmatched code(s), remove X001
NQA104	"# noqa" must have codes, e.g. "# noqa: X000" (enable via noqa-require-code)

Examples

#flake8 noqa   <-- ignored (NQA011)
x = 1+2  #noqa  <-- ignored (NQA001)
x = 1+2  # noqa E226  <-- treated as a blanket noqa (NQA002)
x = 1+2  # noqa : E226  <-- treated as a blanket noqa (NQA003)
x = 1+2  # noqa:  E226  <-- treated as a blanket noqa (NQA004)
x = 1+2 # noqa: X101, E261 <-- unmatched code (NQA103)